The Berne Convention is the keystone to the copyright laws for United States and other 164 countries, which standardized the basics for protection over intellectual work such as music. All the countries party to the Berne Convention may have created additional laws and acts towards extra protection, but never reducing or suspending what has already been set by the Convention. The Berne Convention is administered by the WIPO - World Intellectual Property Organization.
Berne Convention - Summary
Berne Convention - Full text
Is your Country a Contracting Party to the Berne Convention? Check at WIPO.
Copyright Law (link to LII - Cornell University)
Copyright Basics – Circular
1 from the US Copyright Office